Water Quality Assessment Research Articles

Integrating deep learning techniques for effective river water quality monitoring and management

Effective river water quality monitoring is essential for sustainable water resource management. In this study, we established a comprehensive monitoring system along the Kaveri River, capturing real-time data on multiple critical water quality parameters. The parameters collected encompassed water contamination levels, turbidity, pH measurements, temperature, and total dissolved solids (TDS), providing a holistic view of river water quality. The monitoring system was meticulously set up with strategically positioned sensors at various river locations, ensuring data collection at regular 5-min intervals. This data was then transmitted to a cloud-based web portal, facilitating storage and analysis. To assess water quality, we introduced a novel hybrid approach, combining Convolutional Neural Networks (CNN) and Long Short-Term Memory (LSTM) networks. The proposed CNN-LSTM model achieved a validation accuracy of 98.40%, surpassing the performance of other state-of-the-art methods. Notably, the practical application of this system includes real-time alerts, promptly notifying stakeholders when water quality parameters exceed predefined thresholds. This feature aids in making informed decisions in water resource management. The study's contributions lie in its effective river water quality monitoring system, which encompassing various parameters, and its potential to positively impact environmental conservation efforts by providing a valuable tool for informed decision-making and timely interventions.

Pollution-source fractionation and quantification-based assessment of surface water quality in Saigon River, Vietnam: implications for sustainable management strategies

ABSTRACT The current study fractionated pollution sources and investigated the impacts of seasonal and tidal variations on Saigon River’s surface water quality. Ninety-six water samples were collected across dry and rainy seasons, covering ebb and flood tides, and analysed for 19 parameters. During the dry season, ebb tide showed higher levels of electrical conductivity, sulfate, chloride, sodium, and potassium. During the rainy season, ebb tide exhibited greater concentrations of ammonium, total nitrogen, and phosphorus. The water quality index was significantly lower during the dry season’s ebb tide compared to the flood tide but remained similar in both tidal phases during the rainy season. Four primary pollution sources were quantified, with seawater intrusion and agricultural activities contributing 62.68% and 28.54%, respectively, to water quality degradation. Briefly, the river’s surface water quality was inferior during the dry season compared to the rainy season, primarily due to seawater intrusion and agricultural activities, requiring remediation.

In Situ Photoelectrodeposited Polyaniline on Ti‐Doping Hematite For Highly Selective Photoelectrochemical Oxygen Demand Determination

AbstractChemical Oxygen Demand (COD), as a detection indicator of water pollution, is of particular importance in assessing organic pollution in water. Furthermore, accurate and simple measuring COD methods are essential for water quality assessment and pollution control. However, the photoelectrochemical oxygen demand (PECOD) measurement, as one of the measuring COD methods, is affected by the reaction of water splitting, which is one of the hindrances to the commercialization of the analytical method of the PeCOD measurement. Hence, to overcome this challenge, a new PANI/Ti:Fe2O3 photoanode is constructed by hydrothermal and photoelectrochemical (PEC) deposition methods and investigated their optical properties and photoactivity. Under optimization conditions, it is discovered that the oxidation of organic compounds produces a net steady‐state current (inet) is directly proportional to COD concentration, with a detection limit of 1 mM glucose solution and a wide linear detection range of 1–78.125 mM, which is suitable for high concentration of glucose detection. As has been noted, PANI/Ti:Fe2O3 photoanode overcomes the obstacles to the practical application and eventual commercialization of the PECOD technology.

Analysis of the environmental state of the Sarata River in Odesa Region

The relevance of the study is dictated by the need to preserve the water resources of southern Ukraine and ensure their good environmental condition. In the context of military operations, Odesa Region plays a key role in providing the country with agricultural products because of significant damage incurred to agricultural lands of Mykolaiv and Kherson Regions in the course of military actions. Hence the role of irrigation and the need to restore and modernize irrigation systems are growing. One of fresh water reservoirs of Odesa Region is Sasyk reservoir (artificially created as part of the estuary) which accumulates fresh water supplied from the Danube. The Kogylnyk and the Sarata rivers flow into the northern part of the reservoir and can worsen its hydroecological condition. The subject of the study: pollution of the rivers across North-Western Black Sea Coast by chemicals. The object of the study: the environmental state of the Sarata River. The study is aimed at assessing the environmental state and environmental risks of chemical pollution of the Sarata River. The water quality assessment was performed based on a modified version of water pollution index (WPI). Biogenic substances (ammonium nitrogen, nitrite nitrogen, nitrate nitrogen) were identified as the main pollutants. The content of chlorides and sulfates is also significant. The assessment of the pollution risks by biogenic substances is based on calculations of the statistical probit function. The source materials of the research include hydrochemical observations made by the State Agency of Water Resources of Ukraine for the period from 2007 to 2023 in the upper reaches of the Sarata River - village of Miniailivka (94 km from the mouth, near the border with Moldova) and in the lower reaches of the Sarata River - village of Bilolissya (14.3 km from the mouth). The analysis of probability of exceeding the MPC for fishery use indicated that, in terms of nitrite ions and nitrate ions, such probability is higher in the upper basin than in the lower one. According to other indicators, the probability of exceeding the MPC by pollutants is either almost the same or slightly increased in the lower reaches. The assessment of water quality according to the modified WPI (dissolved oxygen, BOD5, ammonium, nitrite and nitrate ions, phosphates) showed that the water quality in the Sarata River mainly belongs to the "moderately polluted" and "polluted" classes. According to the environmental risk indicators, it was established that the possibility of a "high" risk of contamination by biogenic substances does prevail. Its probability is 52.9% for the upper reaches and 60% for the lower reaches. The "high" level of class IV pollution (ER=0.60-0.79) corresponds to an "unsatisfactory" environmental condition. The probability of achieving the class of a "good" environmental condition (class II, ER=0.20-0.39) is quite small: 17.6% in the upper reaches and only 6.67% in the lower reaches. Thus, the Sarata River belongs to such rivers, the natural properties of which underwent significant changes as a result of sewage delivery from "Sarata Komunservis" utility enterprise, settlement of Sarata. Contaminated waters are unsuitable for drinking, household and sports purposes, as well as for fish farming. The quality of the Sarata River's water has a negative impact on the environmental state of Sasyk reservoir.

Assessment of suitability of the Dniester River's water for drinking water supply

The Dniester is a transboundary river between Ukraine and the Republic of Moldova. It is the second longest river in Ukraine and the ninth in Europe. From its source to a town of Staryi Sambir, the Dniester flows through the Carpathian Mountains, then across the flat territory of Ukraine and Moldova. The Dniester Basin extends across seven regions in southwestern Ukraine (Lviv, Ivano-Frankivsk, Ternopil, Khmelnytskyi, Vinnytsia, Chernivtsi and Odesa Regions). A small area of the river in its upper reaches is located in Poland. The basin's shape is a very elongated oval that is curved in the middle, about 700 km long with an average width of 120 km. As it flows into the Black Sea, the Dniester River forms the Dniester estuary in Odesa region (between Ovidiopol and Bilhorod-Dnistrovskyi districts). The estuary area of the Dniester River is a complex landscape system at the sea-river-land contact. Drinking water is an important factor determining a person's health. Due to the intensive development of industry, agriculture and utility services, the number of pollutants that enter the environment and worsen the quality of drinking water in Ukraine keeps increasing. This increases the risk of toxic and infectious diseases spread among the population that consumes such low-quality water. That is why solving the problem of drinking water monitoring and assessment of its quality is a pressing task requiring urgent action. The article examines the quality of water for drinking needs at the water intake site of the Dniester River, a town of Biliaivka, for 2018-2022. Water quality assessment was carried out according to DSTU 4808: 2007 based on average and worst values. The methodology covers 80 indicators and, in accordance with sanitary legislation, is divided into seven separate groups (blocks). According to hygienic standards, the quality of river water is considered suitable for use if it belongs to quality classes 1-3. In this research, the analysis was carried out according to 23 indicators included in three groups, so the assessment is considered as tentative: Group I - organoleptic indicators (chromaticity, turbidity); Group II - general sanitary indicators (dry residue (mineralization), sulfates, chlorides, magnesium, alkalinity, hydrogen index, ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, dissolved oxygen, bichromate oxidation (COD), BSK5); Group VII – toxicological parameters (total iron, manganese, chromium (VI), zinc, petroleum products, synthetic surface active agents (surfactants), volatile phenols). It was determined that, according to the average values, the water quality of the Dniester at the water intake site is characterized as "good", which means it has clean water of acceptable quality. As for the worst indicators, the water was assessed as transitional in quality from "good" (clean) to "satisfactory" (slightly polluted).

Applying the water quality indices and geographic information system approach to assessing the suitability of groundwater quality for drinking and irrigation purposes in the semi-arid region of Tebessa-Ain Chabro, Northeastern Algeria

Assessing the groundwater quality is important for the efficient exploitation of water resources in semi-arid areas. The study area in northeast Algeria mostly depends on groundwater as its main source of water, and the quality of groundwater is becoming important due to the increasing need for freshwater. The hydrochemical characteristics and water quality of groundwater in the Tebessa-Ain Chabro were assessed using water quality indices, geochemical modeling, and multivariate statistical approaches. The study discovered that the groundwater samples could be classified into four distinct water groups using hierarchical cluster analysis in Q mode (HCA) based on their electrical conductivity. We identified three forms of water: mixed (Ca2+–Mg2+–Cl−), Na+–K+–HCO3−, and Ca2+–Cl−. According to the water quality assessment, only 38% of the samples were deemed suitable for human consumption, while 34% were categorized as poor water, 10% as extremely poor, and 17% as unsafe for drinking. The irrigation water quality index identified four classifications: low, moderate, high, and severe restriction, with corresponding percentages of 31%, 31%, 7%, and 31%. The nitrate pollution index (NPI) showed that 48% of samples fell into the moderate pollution class. Human activity, such as sewage infiltration and waste disposal in open areas, was the cause of this nitrate contamination. The saturation index values showed that groundwater was less saturated in halite and sylvite and more saturated in aragonite, calcite, dolomite, anhydrite, gypsum, and hydroxyapatite. The Tebessa region’s groundwater’s hydrochemical properties and water quality have been assessed using multivariate statistical techniques, geochemical modeling, and water quality indexes. The study’s conclusions can provide a foundation for upcoming research evaluating the region’s groundwater quality.

Performance evaluation of a community-based water management organisation using integrated water quality monitoring

ABSTRACT Community-based water management organisations (CBWMOs) play an important role in providing water services worldwide. However, there is some debate as to their capacity to sustain a safe drinking water supply considering the current socioeconomic and climate scenarios. Here, we present an integrated water quality assessment of the supply system of a CBWMO in Concepción of San Ramon, Costa Rica. Major ions, trace metals, and coliforms were analysed in the households and water sources over a 1-year period. The spring risk assessments and the water quality of the main river in the catchment were also carried out. We found that although the supplied water meets adequate standards, spatial and temporal changes in the water quality of the sources exist. Springwater composition is mainly driven by rock–water interaction processes, but early signs of potential anthropogenic pollution were found. The springs showed concentrations of NO3- above natural levels and microbial contamination in 37 and 18% of the cases, respectively. River water quality showed a distinct composition, which is consistent with the anthropogenic pressures in the catchment. This study provides useful information on how water quality assessments can be used beyond regulatory processes to improve planning by CBWMOs to ensure water security.

Conservation of Barilius barila Through Innovative Cultivation: Ecological, Socio-Economic, Ethical Impacts in Bengal and Relevant Legal Issues

The conservation of Barilius barila (locally known as Boroli) is significant for maintaining ecological balance and supporting the socio-economic fabric of North Bengal, India. This study explores innovative cultivation techniques aimed at preserving this species, which is indigenous to the clear streams and shallow rivers of India, Nepal, Bangladesh, and Myanmar. Despite its classification as "Least Concern" by the IUCN, Barilius barila faces threats from environmental degradation, particularly in North Bengal. This research examines the ecological, socio-economic, ethical, and legal dimensions of Barilius barila conservation, with a focus on the artificial cultivation efforts initiated by the West Bengal government in South Bengal. The study employed a mixed-methods approach i.e. water quality assessments, and socio-economic analyses to assess the effectiveness of these conservation strategies. The findings highlight the challenges posed by anthropogenic activities, including pollution, deforestation, and climate change, which have led to the degradation of natural habitats and a decline in the quality of naturally sourced Barilius barila. The research also addresses ethical concerns regarding the potential impact of artificial cultivation on the species' taste and market value which necessitates legal frameworks to support sustainable practices. This study advances the understanding of Barilius barila conservation by providing an analysis of the species' ecological role, the socio-economic implications of its decline, and the effectiveness of innovative cultivation methods. The finding justifies the importance of balancing technological interventions with the preservation of natural habitats, ensuring the long-term sustainability of Barilius barila and its ecological niche in North Bengal.

Phylogenomics resolves a 100-year-old debate regarding the evolutionary history of caddisflies (Insecta: Trichoptera)

Trichoptera (caddisfly) phylogeny provides an interesting example of aquatic insect evolution, with rich ecological diversification, especially for underwater architecture. Trichoptera provide numerous critical ecosystem services and are also one of the most important groups of aquatic insects for assessing water quality. The phylogenetic relationships of Trichoptera have been debated for nearly a century. In particular, the phylogenetic position of the “cocoon-makers” within Trichoptera has long been contested. Here, we designed a universal single-copy orthologue and sets of ultraconserved element markers specific for Trichoptera for the first time. Simultaneously, we reconstructed the phylogenetic relationship of Trichoptera based on genome data from 111 species, representing 29 families and 71 genera. Our phylogenetic inference clarifies the probable phylogenetic relationships of “cocoon-makers” within Integripalpia. Hydroptilidae is considered as the basal lineage within Integripalpia, and the families Glossosomatidae, Hydrobiosidae, and Rhyacophilidae formed a monophyletic clade, sister to the integripalpian subterorder Phryganides. The resulting divergence time and ancestral state reconstruction suggest that the most recent common ancestor of Trichoptera appeared in the early Permian and that diversification was strongly correlated with habitat change.

What is the Difference between Conventional Drinking Water, Potable Reuse Water, and Nonpotable Reuse Water? A Microbiome Perspective.

As water reuse applications expand, there is a need for more comprehensive means to assess water quality. Microbiome analysis could provide the ability to supplement fecal indicators and pathogen profiling toward defining a "healthy" drinking water microbiota while also providing insight into the impact of treatment and distribution. Here, we utilized 16S rRNA gene amplicon sequencing to identify signature features in the composition of microbiota across a wide spectrum of water types (potable conventional, potable reuse, and nonpotable reuse). A clear distinction was found in the composition of microbiota as a function of intended water use (e.g., potable vs nonpotable) across a very broad range of U.S. water systems at both the point of compliance (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.71) and point of use (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.41). Core and discriminatory analysis further served in identifying distinct differences between potable and nonpotable water microbiomes. Taxa were identified at both the phylum (Desulfobacterota, Patescibacteria, and Myxococcota) and genus (Aeromonas and NS11.12_marine_group) levels that effectively discriminated between potable and nonpotable waters, with the most discriminatory taxa being core/abundant in nonpotable waters (with few exceptions, such as Ralstonia being abundant in potable conventional waters). The approach and findings open the door to the possibility of microbial community signature profiling as a water quality monitoring approach for assessing efficacy of treatments and suitability of water for intended use/reuse application.

Perceptions and knowledge about the use of biological indicators in freshwater ecosystem monitoring in Rwanda

The use of biological monitoring (biomonitoring) to assess water quality is recognised alongside the use of chemical and physicochemical parameters due to its ability and efficiency in providing information about both current and long-term changes. Indeed, biomonitoring is applied in several developed and developing countries. Nevertheless, some developing countries, such as Rwanda, are yet to adopt such a monitoring system. This paper presents results of an assessment of the knowledge and perceptions by water resource managers about the use of biomonitoring and bioindicators, and challenges to their integration into existing routine water quality monitoring systems in Rwanda. Qualitative research, using semistructured interviews, was conducted with nine water resource practitioners from six water governance institutions between August and November 2021. The results show that participants are aware that macroinvertebrates, algae and fish are bioindicators that have potential applications in Rwanda to complement the chemical and physicochemical parameters already being collected in the country’s water monitoring system. The main challenges for integration of biological indicators, as indicated by participants, include the need for equipment, funding, technical skills and taxonomic knowledge. Training in the use of bioindicators and taxonomy are needed to raise the awareness and skills of staff from the institutions involved in freshwater ecosystem management in Rwanda, and to encourage integration of biomonitoring results into national water monitoring frameworks.

Assessment of water quality and identification of priority areas for intervention in Guanabara Bay basin, Rio de Janeiro, Brazil, using nonparametric and multivariate statistical methods.

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.

An Assessment of Water Quality and Identification of Problems: A Case Study of Maritimepattu Divisional Secretariat, Northern Province

An Assessment of Water Quality and Identification of Problems: A Case Study of Maritimepattu Divisional Secretariat, Northern Province

Long-term observations of the turbid outflow plume from the Russian River, California

Understanding the mechanisms that spread freshwater away from small river systems and form turbid, low-salinity coastal plumes is crucial for assessing water quality in coastal waters. We present an analysis of 15 years (January 2004 to December 2018) of daily MODIS Aqua satellite data and in situ instrument data on the turbid freshwater plume that forms off the Russian River (California, USA), a prototypical Mediterranean-climate, small mountainous river system (SMRS). We present per-pixel statistical metrics and regression analyses to identify and quantify the controls on the extent and configuration of the plume exerted by river discharge, waves, winds, and tides. While freshwater outflow exhibits a persistent signal in nearshore waters, a large-scale plume only extends offshore into coastal waters during high river flow, when plume turbidity can be detected more than 10 km offshore from the river mouth. Our results show times when wave radiation stress exceeds outflow inertia, confining the plume within the surf zone and leading to an absence of detectable plume turbidity in coastal waters. Although tidal currents significantly influence the plume near the inlet, wind forcing is the primary control on plume shape and extent in coastal waters, deflecting the turbid outflow more than 30 km upcoast or downcoast of the river mouth with respective wind directions. Coriolis forcing is also significant and observed most clearly during periods of high river discharge and low wind forcing. In addition to introducing novel remote sensing methodology for SMRS plume analyses, these findings highlight the complex interplay of forcing related to tides, river discharge, winds, and waves in shaping the behavior of SMRS plumes. New insights include the impact of tides on larger discharges, the role of Coriolis forcing in SMRS plumes, and the effect of cross-shore winds on plume compression. Further, by considering the Russian River as a model for SMRS, this study can be used to ground-truth existing numerical models of small river plumes and to contribute to understanding critical for managing coastal water quality and nearshore ecosystems.

Assessing water quality of kazerun county in southwest Iran: Multi-analytical techniques, deterministic vs. probabilistic water quality index, geospatial analysis, fuzzy C-means clustering, and machine learning

Water quality is critical to human health and the environment, especially in arid and semi-arid regions. Hence, the objectives of this study were to assess drinking water quality, identify critical parameters, investigate spatial patterns, and investigate accurate predictive models for the water quality index (WQI) in the Kazerun county in southwest Iran. To address this issue using deterministic and probabilistic WQI, correlation matrix, fuzzy C-Means (FCM) clustering, geostatistics, and adaptive network-based fuzzy inference system (ANFIS) with FIS generation by fuzzy C-Means (FCM-ANFIS) and sub-clustering (SC-ANFIS).Various software tools, including Excel, MATLAB, Python, and GIS were used to analyze groundwater data collected from 25 sampling sites. Water parameters, including pH, Cl−, SO4−2, EC, NO3−, NO2−, Ca2+, Mg2+, and F−, were examined. The results showed that F− levels were within acceptable limits set by the US EPA, but about one-third of sites posed potential health risks based on WHO guidelines. In one-third of regions, the levels of Mg2+ exceeded the recommended guidelines. In deterministic and probabilistic approaches, water quality was excellent in 68% and 81.3% of sites, respectively. Sobol sensitivity analysis identified SO4−2> Mg2+>Cl− > EC > F− > NO3− as significant WQI variables. Spearman correlation matrix shows substantial positive correlations between WQI and EC, F−, SO4−2, Mg2+, and Cl− were shown by the Spearman correlation matrix. Based on the FCM results, the southeast and central sites (56% of sites) have similar water quality. In comparison, the northern and four central sites (28% of sites) have distinct regional features, and the southern sites (16% of sites) had unique water quality characteristics. Geostatistical analyses showed that pH had the most substantial local clustering, while SO4−2 had significant high-value clustering. Furthermore, hot spot research revealed specific sites with high pH, F−, NO3−, and Cl− levels. The FCM-ANFIS model outperformed the SC-ANFIS model, emphasizing FCM clustering's importance in water quality forecasting accuracy.

The Application of the Game-Gray Target Model on the Water Quality Assessment in the Tao Jiang River

The Application of the Game-Gray Target Model on the Water Quality Assessment in the Tao Jiang River

Plankton and contour algal communities in the Ukrainian section of the Western Bug River and its tributaries

The paper deals with spatial dynamics of cell count, biomass, dominant species complexes, information diversity of planktonic and contour algal communities in the Western Bug River and its tributaries. The trophic state and water quality of the rivers under study have been assessed. The spatial heterogeneity of phytoplankton, microphytobenthos and phytoperiphyton brought about high cell count and biomass values during the low-water summer-autumn season. The cell count and biomass have been shown to increase from the upper reaches downstream, correlating with the river bed width. High quantitative diversity of algal communities was due to Bacillariophyta dominance. Cyanobacteria and Chlorophyta were recorded as subdominants. The trophic state of the aquatic ecosystems under study varied between oligotrophic and eutrophic. The Shannon’s index made up 1.58–4.62 bit/cell and 1.60–4.40 bit/mg. The trophic state and information diversity assessed according to contour algal communities were higher than according to phytoplankton. This is indicative of the clear water regime forming in the rivers under study during the low-water summer-autumn season. The obtained findings differ from the data, published earlier for the Kaniv Water Reservoir, where the primary role belonged to phytoplankton. The spatial heterogeneity of algal communities is related to the dominant complexes structure. As a rule, these are monodominant Bacillariophyta complexes or oligodominant Bacillariophyta – Cyanobacteria or Bacillariophyta – Chlorophyta complexes. The water quality assessment according to the abiotic variables and saprobiologic characteristics has shown that the modal classes of water quality are the 2nd–3rd classes (clean waters – satisfactory clean waters). Therefore, the water quality of the Ukrainian section of the Western Bug River and its tributaries does not pose any substantial hazard to the adjacent European countries.

Ecological Structure of Macrobenthic Invertebrates of the Benin River, Southern Nigeria, Before the Seaport Development Project

Macrobenthic invertebrates are major components of aquatic ecosystems. Because of their partial or sessile motion, they can be used to assess water quality status. The Benin River is a beehive of human activity, and with the development of the proposed seaport along its course, its physical, chemical, and biological components may be affected. The need to document macrobenthic invertebrates before the seaport development prompted this study. Four stations were selected between Ajoki and a section opposite Young Town, employing both kick sampling and Ekman grab techniques. Seasonal influence on the distribution and abundance of macrobenthic invertebrates was observed. In total, 3,267 macrobenthic invertebrates were collected during the sampling period. The highest number of taxa (35) were recorded in Station 1, and the highest number of individuals (1,103) was in Station 3. The dominant macrobenthic invertebrate group was Decapoda (76.61%); Diptera (6.15%) and Ephemeroptera (4.62%), others constituted the remaining 12.62%. There was a positive correlation between the family Diaptomidae and the physicochemical parameters, except for heavy metals.

Water Quality Assessment and its Impact on Shrimp in the Rupnarayan River: A Comparative Study from February to May of 2022-2024

The Rupnarayan River is the heart of the Purba Medinipur district of West Bengal, as it is the habitat of a large number of aquatic species and the main drinking, agricultural, irrigation, and cultivation resource. We collected river water samples from the Kolaghat, Alinan, Siuri and Deemari villages near Tamluk in the Purba Medinipur district. Then, we assessed different water quality parameters, such as temperature, turbidity, pH, DO, BOD, salinity, alkalinity, and hardness. We studied the premonsoon phase (Feb-May) and assessed the impact of these parameters on the production of shrimp species. We identified M. rosenbergi, M. brevicornis, M. monoceros, and Penaeus vannamei as shrimp species. We also compared the data from 2022 to 2024 (Feb-May) and observed yields of 40%, 60%, and 30% in 2022, 2023 and 2024, respectively.

Water Quality Evaluation and Spatial-temporal Distribution Characteristics of the East Route of the South-to-North Water Diversion Project in Jiangsu Province Based on WQI

The east route of the South-to-North Water Diversion Project in Jiangsu Province was used as an example to investigate the characteristics of changes in water quality in the area affected by significant water diversion projects. Based on the comprehensive assessment method of the water quality index （WQI）, the M-K trend test, and the geographic information system （GIS）, the spatial and temporal variation characteristics of water quality in the 13 national assessment sections of the east route of the South-to-North Water Diversion Project in Jiangsu Province were evaluated and analyzed from 2013 to 2022. The results showed that the water quality assessment grades in the study area were mainly "medium" and "good." The overall mean value was 74.03, indicating "good" water quality. DO, BOD5, and NH4+-N were the primary indicators of changes in river water quality in the region. Over time, the water quality in the basin had significantly improved from 2013 to 2022. However, there was a rebound in 2021, but this phenomenon was effectively controlled in 2022. Water quality was better during the non-flood season compared to that during the flood season. From a spatial perspective, the water quality in the southern part of the region was superior to that in the north. Furthermore, the rate of improvement was faster in the south. This could be attributed to factors such as precipitation, population density, and the scale of agricultural and livestock activities. However, the water quality of the S11 （Sanduoxi Bridge） section was generally lower than that of other sections and should be given further attention.